Numerous problems have been encountered in both the manufacture and use of conventional fitted sheets. Conventional fitted sheets typically employ various combinations of seams and/or elastic bands at the corners. The contoured corners thus formed are intended to fit snugly over the corners of an underlying mattress whenever the sheet is in use.
Bed linen manufacturers generally produce conventional fitted sheets having a single set of dimensions for each standard bed size, difficulties frequently arise when the sheets are used by the consumer. When the conventional fitted sheets are placed over a relatively thinner or smaller mattress, the corners may not fit snugly, causing the sheet to bunch or wrinkle across the bed surface, making the bed uncomfortable and unattractive. Conventional fitted sheets are used with relatively thicker or larger mattresses, it is often difficult to stretch the last corner over the mattress, and ripping or tearing of the corner construction may occur, particularly after repeated use and laundering. In addition, conventional fitted sheets require the end user to lift at least one corner of the mattress to place the fitted sheet on the mattress.
Contoured or fitted sheets overcome some of the problems associated with flat bedsheets by sewing an elastic strip around the bottom corners of the sheet to create pockets which fit around the four corners of the mattress. The sheet is tucked under the mattress for three corners than on the forth corner, the mattress is lifted up to allow the pocket of the sheet to be slipped over the corner of the mattress. Principle disadvantages of conventional fitted sheets are they often wear out at the pockets, are bulky to store, wash, and handle and that the end user must lift up the mattress to allow the pocket of the sheet to be slipped over the corner of the mattress.
U.S. Pat. No. 5,173,976 to Jubinville discloses a mattress cover/fitted bedding top sheet which consists of a substantially rectangular blank of textile material with opposed sides and opposed ends. A pair of generally triangular pieces are cut out of the opposed sides adjacent the ends. Each of the triangular cut outs has a pair of opposed sides, an apex directed inwardly on the textile material and a base coincident with one of the sides of the textile material. The sides of the triangular cut outs are joined to form a biased side seam such that, when placed on a mattress, textile material is drawn under the end of the mattress.
U.S. Pat. No. 6,983,500 to Wootten discloses a fitted cornerless bedclothing item such as a sheet, mattress pad, anti-allergy cover, blanket or coverlet includes a top portion, side portions and end portions, and elastic segments stitched to edges of respective side and end portions. One or more elastic bindings are provided at lower edges of the side and end portions to cause the tops of the elastic segments to be positioned below the respective upper corners of the mattress on which the bedclothing item is mounted, such that no ears or pockets are formed when the bedclothing item is mounted on mattresses of at least two different sizes and/or thicknesses. The elastic segments are made of knitted or woven elastic filaments, such as SPANDEX® fabric, and can be shaped to have a straight lower edge and a curved upper edge, the curved upper edge advantageously approximating an end of an ellipse.
U.S. Pat. No. 4,245,365 to Large, et al. discloses a fitted top contour sheet having an end pocket receiving the rear of a mattress and pairs of hooks and eyes to secure the bottom of the pocket to the mattress.
U.S. Pat. No. 4,912,790 to Macdonald discloses a fitted bedding top sheet includes a substantially rectangular main body portion of substantially the same dimensions as a selected mattress. Side portions extend from the sides of the main body portion and terminate in longitudinal edges. End portions extend from the ends of the main body portion and terminate in end edges. Substantially vertical corner seams join the side portions to the adjacent end portions, each seam extending from an inner end at a corner of said main body portion to an outer end at the junction of a longitudinal edge and an end edge. The side edges and end edges are thereby joined together to define a perimeter. There is elastic in at least a portion of the perimeter, to permit the sheet to fit snuggly around a mattress. Macdonald discloses that the vertical corner seams are at least partly elasticized.
U.S. Pat. No. 5,165,128 to Honig discloses a fitted bedding top sheet of a generally rectangular blank of fabric material having two bottom corners, each corner cut away by three curved lines to form a junction having an angle of substantially 90 degrees, to each of which a band of stretchable material is sewn, in stretched condition, to the outside edge of the cut corners and along the entire edge portion of the bottom of the blank, which cut corners are then joined by stitching at each corner and bottom edges thereof, thereby forming two expandable pockets for engaging the bottom corners and bottom portion of a mattress.
Other patents disclosing fitted bedding top sheets, or variations thereof, include U.S. Pat. No. 2,598,141 to Simpson, U.S. Pat. No. 2,605,483 to Ridenhour, U.S. Pat. No. 3,013,283 to Steffinich, U.S. Pat. No. 3,638,252 to Palenske, U.S. Pat. No. 3,832,743 to Smith, U.S. Pat. No. 4,045,832 to DiForti, U.S. Pat. No. 4,095,300 to Ruben, U.S. Pat. No. 4,384,380 to Glaha, et al., U.S. Pat. No. 4,964,184 to Lewis, U.S. Pat. No. 5,029,353 to Kimball et al., U.S. Pat. No. 5,084,929 to Staudinger, U.S. Pat. No. 5,729,847 to Allardice, U.S. Pat. No. 6,041,456 to Pharr, U.S. Pat. No. 7,293,306 to Hermanczuk, U.S. Pat. No. 7,380,297 to Bauer, U.S. Patent Publication No. 2004/00255381 to Generalovich II, U.S. Patent Publication No. 2007/0151028 to Bauer, U.S. Patent Publication No. 2009/0044337 to McKee, and non-US Patent document GB2292075A to Wong.
The use of stitched darts and/or elastic to form the fitted corners as disclosed in the foregoing patents requires the use of manufacturing procedures that are more complicated and expensive than would be needed if such stitching were not required. Furthermore, sheets made in such manner cannot be laid out flat, and are therefore more difficult to fold, package and store.
The use of VELCRO fasteners(hook and loop fastners) with sheets is also disclosed in U.S. Pat. Nos. 3,832,743 and 4,241,466. These patents disclose the use of releasable fasteners for separably fastening one edge of a bedding top sheet to a side or end panel of an underlying bottom sheet to prevent the bedding top sheet from coming loose or untucked during use.